This invention relates generally to plastic bags and closures therefor. More particularly, the invention relates to closures for plastic bags designed for carrying food products and the like to maintain those products in useable condition.
This explanation will be directed rather specifically to plastic bags used for storing food products and other perishable items. However, it should be understood that the structures disclosed in this application would be useful for many other purposes and it is not intended that this application be limited to plastic bags for food products.
It is not uncommon after dinner is over for the cook to gather up the left-over food, put it in various plastic bag containers and then put them in the refrigerator for use at a later time. Generally, when doing this it is desirable to somehow close the plastic bag or seal it to maintain the food products in as fresh a condition as possible. Such things as metal ties have been used for this purpose. Clamps and other devices have also been used. All of these have the disadvantage that they are not attached to the bag itself so that they must be obtained from some other source and added to the bag. Furthermore, frequently, they are not satisfactory. There are numerous patents that have been issued in this area, for example, see U.S. Pat. No. 5,054,168 which discloses a horizontal clip closure, U.S. Pat. No. 4,928,829 which also discloses a horizontal clip closure, U.S. Pat. No. 4,866,818 which discloses a pinched clip designed to be snapped horizontally around the opening of the bag, U.S. Pat. No. 4,887,335 which discloses a horizontal clip for use in closing plastic bags and other patents which will be listed in the disclosure statement for this patent application. None of these devices perform the function of closing the bag opening in a satisfactory fashion, so that they easily close the opening and provide a suitable atmosphere for maintaining food products.
The disadvantage of these prior art devices, in general, is that they are horizontal closures, i.e., operate horizontally or parallel to the opening of the bag. These devices are also separate from the bag. Thus, they must be added to the bag before they can be made useful for closure purposes.
Another popular resealable bag is the zipper or profile bag, such as the bags manufactured by Dow Chemical under the registered trademark ZIPLOCK. Those bags contain a zipper or interlocking profiles at the mouth of the bag which permit the user to selectively open and reseal the bag many times.
The zipper bag is typically a plastic bag having a front wall and a back wall with opposing and corresponding interlocking profiles on the inner sides of each wall. The profiles are generally located at or very near the opening of the bag, with a lip of bag wall extending above the opening to aid the user in reopening the bag. Other variations of the zipper bag include a slide which is used to open and close the profiles. As the slide is drawn across the profiles, it opens the bag if drawn in one direction, and seals the bag if drawn in the other. The bags equipped with a slide typically do not have a lip extending above the profiles as such a lip would interfere with the slide. Further, the lip is not necessary to open the profiles since the slide performs that function. The slide also performs the function of aligning the profiles, thus reducing the frustration of the user in trying to align the profiles.
The profiles of a zipper bag generally run substantially the entire length of the opening such that when they are interlocked, they form a seal across the entire bag opening. While making an effective seal, these bags are not without their disadvantages.
Conventional recloseable deli bags, using the standard zipper or a slide, do not prevent the food or other products from coming in contact with the zipper profiles since the zipper profiles are located on the inside of the bag. This causes food or other substances to be raked off onto the profiles when items are placed in or removed from the bag. The food or other substances can become embedded in the profiles, therefore making them difficult or impossible to engage.
The snap closure as described in this present application is completely outside the bag and will not come in contact with the product being loaded or removed. A particular advantage to this type of construction for closing a plastic bag is the fact that the closure is literally part of the bag. It does not have to be added at a later time. Prior art closures have normally been horizontal closures which would go across the top of the bag and then hooked, enclosing the opening of the bag within the closure. These have closed and sealed satisfactorily but the fact that they must be separate from the bag or in some way difficult to attach to the bag, has made them less than desirable for closure purposes. Also, since the opening of the bag is within the closure, the closure must be adapted with a means by which to reopen the closure and bag. The snap closure of this invention obviates those problems and allows the user to seal the bag rather readily and quickly and effectively to carry any items of desire in the plastic bag with the opportunity of easily opening the snap closure to allow access to the bag. The ease of opening is accomplished as a result of having the mouth of the bag extend outward from the closed closure rather than being contained within the closure. To open the closure, the user need only grasp the exposed mouth of the bag and pull, thereby disengaging the closure.
Traditional recloseable profiles are affixed to both the inner front and back walls of the bag. The profiles are stiff members that make the bag difficult to open or receiving product. The bags tend to want to close such that the stiff profiles are in contact, but not placed together with enough force to seal. This can make it difficult to place a product in the bag because one hand is required to keep the bag opening open in such a way that the other hand can place the product into the bag.
The traditional recloseable profiles also require that each end of the profile sections be crimped by sonic welding, heat sealing, or any other mechanical means. The crimping of the ends aligns the profiles and reduces the thickness of the edges of the bag for cutting and sealing when manufactured. This crimping reduces the effective opening of the bag, resulting in a bag that is more difficult to open and load. The closure described in the present application is relatively flat, limber, and is only affixed to one side of the bag. Although it is crimped at the end, it is only crimped on one wall of the bag, and thus the crimping does not affect the opening of the bag to the same extent that the crimping of the traditional recloseable profiles does. The result is the bag of the present application opens easier and can be loaded faster.
The conventional profiles excluding those that include a slide, need to be aligned by the customer even though they are crimped for that purpose. The motion of aligning the profiles takes time and can be frustrating as the profiles do not always align correctly. It can also be difficult to determine whether the profiles are correctly engaged to effect a seal. It is not always apparent by merely looking at the closure. Some manufacturers have employed different colors on each of the profiles such that when they are placed together correctly, the color of the profiles appears different when the bag is correctly sealed. The closure of the present invention does not require alignment. The closure is automatically aligned when folded about its hinged section. This reduces a customers time and frustration level in closing the bag.
Reopening a bag using conventional profiles can also be difficult. The conventional profiles are opened by grasping the top of each bag wall with a separate hand, and pulling the walls apart to separate the profiles and open the bag. The closure of the present invention is easier to open. The user need only pull on the exposed mouth of the bag to open the closure. This can be accomplished with one hand or even with one's teeth.
Accordingly, it is an object of this invention to provide a snap closure for the mouth of a plastic bag which is attached to the bag itself and may easily be closed to seal the opening thereof. It is a further object of this invention to provide a closure for the mouth of the bag that is flexible and attached to only one wall of the bag. It is a further object of this invention to provide a closure for the mouth of the bag that will not become fouled by the product placed in or removed from the bag. It is further an object of this invention to provide a plastic bag with a closure that may be opened by pulling on the exposed top of the bag, without the need to separate the walls of the bag.